-NRLF 


GIFT  OF 


General  Specifications 

for 

Electric  Overhead  Traveling  Cranes 
Heavy  Duty  Steel  Mill  Service 


,  Association  of  Iron  and  Steel 
Electrical  Engineers 

1007  Empire  Building 
Pittsburgh.   Pa. 


Presented  at  the 

Fifteenth    Annual    Convention 

September   19-24,   1921 


GENERAL  SPECIFICATIONS  FOR  ELECTRIC 

OVERHEAD  TRAVELING  CRANES 
HEAVY  DUTY  STEEL  MILL  SERVICE 

AS   RECOMMENDED  BY 

THE  CRANE  STANDARDIZATION  COMMITTEE  OF  1921 

F.  W.  CRAMER,*  Chairman 

1.  Title. 

These  specifications  shall  be  known  as  the  "Association  of 
Iron  and  Steel  Electrical  Engineers  Specifications"  and  if  in- 
cluded in  a  contract  as  such,  shall  form  a  part  of  that  contract, 
whether  attached  to  it  or  not. 

2.  Scope  and  Application. 

It  is  intended  these  specifications  shall  apply  to  heavy  duty 
steel  mill  cranes,  and  as  far  as  practical  to  cranes  for  special 
service  such  as  stripping  ingots,  charging  ingots  into  and  draw- 
ing them  out  of  soaking  pits,  ore  handling,  charging  open  hearth 
furnaces,  etc.  It  is  not  intended  they  shall  take  precedence 
entirely  over  specifications  for  special  cranes  or  over  ordinary 
or  light  duty  cranes  for  general  purposes. 

3.  Proposals. 

When  inviting  proposals,  purchaser  shall  submit  supple- 
mentary specifications  containing  principal  dimensions,  capacity, 
electric  current  available,  and  any  unusual  requirements. 

Builder  shall  submit  with  proposal  full  description  covering 
the  design  and  construction  of  the  crane. 


*Engineer  of  Tests,  Cambria  Steel  Company,  Johnstown,  Pa. 


5078 j 7 


2  A.I   &'$.*& 

4.  Drawings  and  Specifications. 

On  acceptance  of  proposal,  two  copies  of  specifications  shall 
be  furnished  to  the  purchaser  and  on  completion  of  the  crane 
two  sets  of  working  drawings  shall  be  supplied.  Such  specifica- 
tions and  drawings  shall  be  treated  by  the  purchaser  as  con- 
fidential information  and  shall  be  used  only  for  the  purpose  of 
insuring  the  fulfillment  of  the  contract  or  as  a  guide  in  main- 
taining the  crane  in  proper  condition. 

5.  Superintendence  and  Acceptance. 

If  stipulated  in  the  specifications,  builder  shall  furnish  super- 
intendence for  erecting  and  operating  the  crane  for  a  fixed 
period  to  demonstrate  that  it  complies  with  all  requirements. 
Compliance  with  the  specifications  shall  be  determined  by  in- 
spection after  delivery  and  proper  tests  made  under  maximum 
working  load. 

6.  Material,  Workmanship  and  Inspection. 

Material  and  workmanship  shall  be  of  best  quality  and  shall 
be  subject  to  the  inspection  by  the  purchaser  at  any  time.  On 
request  builder  shall  furnish  purchaser  or  his  representative  full 
information  concerning  the  material  entering  into  the  con- 
struction. 

7.  Strength  of  Material. 

(a)  Proper  provision  shall  be  made    for  all   parts   subject 
to  impact  and  rough  usage.    Journals  and  shafts  shall  be  of  suf- 
ficient size  to  bring  bearing  pressures  and  deflections  within  safe 
and  practicable  limits. 

(b)  Fibre  stress  in  cast  iron  shall  in  no  case  exceed  2,000 
pounds  in  tension,  or  8,000  pounds  in  compression.    Fibre  stress 
in  cast  steel  shall  in  no  case  exceed  8,000  pounds  in  tension  or 
10,000  in  compression. 

(c)  Wrought  iron  and  structural  steel  as  regards  physical 
properties,   shall   conform   with   "The   Manufacturer's    Standard 
Specifications." 

8.  Kind  and  Quality  of  Material. 

(a)  All  castings  shall  be  of  steel  unless  otherwise  specified, 
except  brake  shoes  and  drums,  which  may  be  of  cast  iron. 

(b)  If   purchaser   desires   a   special   type   of   collector   shoe 
he  shall  supply  builder  with  drawings  of  same. 


A.  L  &  S.  E.  H.  CRANE  SPECIFICATIONS  3 

(c)     All  castings  shall  be  of  best  material,  free  from  blow- 
holes or  other  injurious  defects. 

9.  Factor  of  Safety  at  Rated  Capacity. 

(a)  Load  hook  not  less  than  10. 

(b)  Hoist  shafting  and  all  gears  not  less  than  6. 

(c)  All  other  parts  not  less  than  5. 

10.  Accessibility. 

(a)  All  parts  which  may  require  occasional  removal  or  re- 
placement shall  be  readily  accessible. 

(b)  All  lubricating  devices  shall  be  conveniently  located. 

1 1 .  Inter  changeability. 

As  far  as  practical,  corresponding  parts  of  a  crane  shall  be 
alike  and  interchangeable. 

12.  Gears  and  Covers. 

(a)  All  gears  and  pinions  shall  be  cut  to  diametrical  pitch, 
Brown  and  Sharpe  standard  involute  teeth. 

(b)  All  pinions  shall  be  made  of  open  hearth  steel  unless 
otherwise  specified. 

(c)  No  split  gears  shall  be  allowed. 

(d)  Overhung  gears  shall  be  used    only    with    purchaser's 
approval. 

(e)  All   gears  shall   be  protected  by  gear   covers   arranged 
so  that  top  part  can  be  removed  for  inspection  and  repairs  with- 
out disturbing  lower  part. 

(f)  The  builder  shall  use  the  motor  manufacturers'  standard 
gear  ratios. 

13.  Shafting. 

(a)  All   shafting   shall   be   increased    at    least     ^6 -inch    in 
diameter  for  the  hub  fits  of  gears,  pinions,  track  wheels  or  drums, 
except  when  these  are  located  at  the  end  of  the  shaft. 

(b)  All   shafting  6  inches   or  less   in   diameter   not   having 
increased  diameter  for  hub  bearings  may  be  cold  rolled  or  drawn. 
All  shafting  having  increased  diameters   for  hub  bearings,  and 
all  shafting  above  6  inches  in  diameter,  shall  be  forged  and  turned 
to  size. 

'(c)  The  minimum  diameter  of  bridge  line  shafting  shall 
be  3^  inches.  Starting  with  3^  inches,  the  standard  diameters 
shall  run  in  even  34-inch  sizes. 


4  A.  I.  &  S.  B.  H.  CRANE  SPECIFICATIONS 

(d)  End  sections  of  bridge  drive  shaft  shall  be  4  feet  long 
and  interchangeable. 

(e)  Middle  section  shall  be  8  feet  long. 

14.  Press  Fits. 

All  parts  subject  to  torsion  are  to  be  pressed  or  shrunk  on 
to  the  shaft  and  keyed  in  place. 

15.  Brackets. 

(a)  Bearing  brackets,  if  not  cast  integral  with  frame,  must 
be  kept  in  alignment  by  male  and  female  joints  or  other  equally 
effective  method.     Holding  bolts  shall  not  be  depended  on   for 
this  purpose. 

(b)  Duplicate  brackets  shall  have  holding  bolt  holes  drilled 
to  template  so  as  to  be  interchangeable. 

(c)  Tie  brackets,  made  in  a  single  piece,  shall  be  provided 
to  tie  all  driving  and  driven  shafts,  and  shall  be  located  as  close 
as  possible  to  pinion  and  gear. 

(d)  Where  brackets  or  other    supporting    parts    requiring 
accurate  alignment,  are  attached  to    structural    material,    unless 
such   stuctural   material   is   of   sufficient   thickness   to   allow    for 
finishing,  heavy  planing  strips  shall  be  riveted  to  structure ;  these 
strips  and  parts  that  are  attached  to  them  must  be  assembled 
with  their  contact  faces  machined. 

16.  Bearings. 

(a)  All  track  wheels  unless  otherwise    specified    shall    be 
provided  with  type  of  bearings  known  as  Master  Car  Builders 
or  "M.   C.   B."  type.     The  bearing  linings   shall  be  flanged   at 
each  end.     Construction  of  bearings  shall  be  such  as  to  permit 
"lining  up"  to  compensate  for  wear. 

(b)  All  bearings  except  on  motors,  sheaves  and  track  wheel 
pins,  shall  be  fitted  with  caps,  finished  male  and  female.     They 
shall  be  accurately  bored  and  lined  with  split  bushings  having 
flanges  on  each  end  to  hold  them  in  place,  and  proper  provision 
shall  be  made  to  keep  the  bushings  from  turning. 

(c)  Bottom  half  of  bearing  lining  shall  be  so  designed  as  to 
permit  of  removal  and  replacement  without  removing  shaft. 

17.  Lubrication. 

Grease  cups  shall  be  provided  for  all  bearings  except  those 
for  wheels  or  motors.     They  shall  have  standard  pipe  threads 


A.  I.  &  S.  E.  H.  CRANE  SPECIFICATIONS  5 

and  as  far  as  possible,  be  located  at  points  accessible  from  foot 
walks.  Type  of  grease  cups  to  be  specified  by  purchaser  if 
there  is  a  preference. 

18.  Shaft  Couplings. 

(a)  The  standard  A.   I.   &   S.   E.   E.   coupling  shall  be   so 
designed  that  the  same  coupling  can  be  used  on  all  sizes  of  line 
shafting  from  3^  inches  to  4^  inches  diameter  inclusive. 

(b)  It  shall  have  a  straight  face,  a  10-inch  bolt  circle  and 
six  1-inch  holes  for  body  bound  bolts. 

(c)  This  coupling  for  safety   reasons   must  be   covered   by 
a  guard. 

19.  Bolts,  Ntits  and  Rivets. 

(a)  Bolts  not  otherwise  specified,   shall  be  rough  machine 
bolts,  U.  S.  Standard  threads,  with  cold  punched  hexagon  nuts. 

(b)  Bolts   shall   be   provided   with   lock   nuts.      Inaccessible 
bolt  heads  shall  be  held  in  some  way    to    prevent    bolts    from 
turning. 

(c)  Studs  or  cap  screws  are  not  to  be  used. 

(d)  Bolts  are  to  be  so  located  if  possible  as  not  to  require 
the  use  of  socket  wrench  or  other  special  wrench. 

(e)  In  fabricating  and  assembling  structural  work  such  as 
gusset  plates,  brackets  supporting    foot-walks    and    bridge    line 
shaft,  angles  supporting  operator's  cab,  and  all  other  parts  rivets 
shall  be  used  instead  of  bolts  wherever  practicable. 

20.  Stairs  and  Ladders. 

(a)  Stairs  shall  be  provided  in  preference  to  ladders.     Stair 
treads  shall  be  of  material  designed  to  prevent  slipping,  and  shall 
not  be  less  than  18  inches  in  length.     Where  stairs  are  not  con- 
structed with  risers,  a  plate  shield  shall  be  attached  to  the  under 
side,  extending  the  entire  length. 

(b)  Where  ladders  must  be  provided  they  shall  be  of  steel 
and  constructed  with  square  rungs  to  prevent  turning.     The  rails 
shall  extend  42  inches  above  landing  place  at  top,  for  safety  in 
getting  on  or  off  the  ladder. 

(c)  Where  the  slope  of  stairs  exceeds  an  angle  of  55  degrees 
from  the  horizontal,  ladders  shall  be  used  in  preference  to  stairs. 


6  A.  I.  &  S.  E.  E.  CRANE  SPECIFICATIONS 

21.  Footwalks. 

(a)  Unless  otherwise  specified   steel   footwalks  with  rough 
tread,  not  less  than  J^-inch  thick  and  24  inches  wide  shall  be 
provided  on  outside  of  both  girders,  extending  to  web   of  the 
girders  and  full  length  of  crane  and  where  practical  over  end 
carriages  and  cab  making  it  continuous    around    top    of    crane. 
Where  only  one  such  footwalk  is  installed  on  the  crane,  it  shall 
be  on  the  side  carrying  the  bridge  motor.     When  motor  is  not 
located  entirely  below  floor  of  walk,  the  walk  shall  be  widened 
at  the  motor  to  give  a  clearance  of  not  less  than  15  inches  be- 
tween  railing   and   motor.      Where   motor   is   located   partly    or 
entirely  below  footwalk  it  must  be  surrounded  by  a  plate  cor- 
responding to  the  footwalk. 

(b)  When   practicable,   a   footwalk   with    railing    of    same 
material   and   same   general   construction   as   walks   and   railings 
on  bridge  girders,  or  just- a  railing,  shall  be  provided  across  ends 
of  trolley. 

22.  Railings. 

All  railings  shall  be  made  of  structural  steel ;  shall  be  of 
standard  construction,  not  less  than  42  inches  high,  with  toe 
boards  not  less  than  4  inches  high  with  intermediate  member  21 
inches  high. 

Railings  shall  be  provided  on  girder  footwalks  and  ends  of 
bridge,  landing  on  cab,  and  on  stairs  leading  to  bridge  girder 
from  landing  on  cab. 

23.  Box  -for  Supplies. 

A  steel  box  for  storing  oil,  grease  and  waste,  made  of  steel 
plate  and  provided  with  hinged  lid,  shall  be  fastened  to  girder 
side  of  .footwalk. 

24.  Bridge  End  Carriages. 

(a)  Carriages   shall   be   made   either   of   cast   or   structural 
steel. 

(b)  They  shall,   where  practicable,  have  bearings   on  both 
sides   of   driving   pinions   cast   integral   with   carriage.      Flanges 
shall  be  on  outside  to  afford  easy  access  for  bolting  or  riveting. 

(c)  Heavy  lugs  shall  extend  across  the  bottom  of  each  car- 
riage near  each  track  wheel  and  one-inch  above  the  rail  to  pre- 
vent excessive  drop  of  crane  in  case  of  breakage  of  track  wheel 
pin  or  carriage. 


A.  I.  &  S.  H.  E.  CRANE  SPECIFICATIONS  7 

(d)  No  part  of  carriage  or  track  wheel  gears  shall  project 
below  the  flange  of  track  wheels. 

(e)  Pads   shall   be  provided    for   use   of    iacks   or  wedges 
when  changing  track  wheels.     Carriage  and  track  wheels  shall 
be  so  designed  as  to  permit  of  changing  the  wheels  by  raising  the 
carriage  just  enough  to  free  the  bearings. 

(f)  Bumpers  shall  be  provided  on  each  end. of  the  carriages 
for  protection  of  crane  in  case  of  collision  or  one  crane  being 
required  to  push  another.     Location  and  type  of  bumpers  to  be 
specified  by  purchaser. 

(g)  Where  necessary,  steps  or  ladders  must  be  provided  to 
give  access  to  compensating  trucks  from  track  girders. 

(h)  Guards  which  will  shove  forward  or  off  the  track  any 
object  placed  across  it,  like  a  person's  foot  or  arm,  shall  be 
attached  to  each  end  of  the  carriages. 

25.     Track  Wheels. 

(a)  Track  wheels  shall  preferably  be  of  rolled  or   forged 
steel.     Cast  steel  wheels  may  be  used  if  specified. 

(b)  The   standard    tread   diameter   of    bridge   track   wheels 
shall  be   18-inch,  24-inch,  27-inch  and  30-inch,   and  tread   shall 
be  made  to  suit  a  standard  rail  not  smaller  than  85  pounds  sec- 
tion.    Treads  for  heavier  rails  to  be  made  to  suit. 

(c)  The  standard  bores  of  these  wheels  shall  be  as  follows: 

18-inch  diameter  45/6-inch  bore 

24-inch  diameter  55/6-inch  bore 

27-inch  diameter  65/6-inch  bore 

30-inch  diameter  75/6-inch  bore 

(d)  A  standard  increase  in  diameter  of  J/^-inch  for  all  bridge 
track  wheel  axles  in  the  wheel  hubs  is  recommended. 

(e)  All    bridge   track    wheels    on    same   crane    to   be    inter- 
changeable. 

(f)  The  A.  I.  &  S.  E.  E.  standard  for  bridge  runway  rails 
shall  be  an  85-pound  open  hearth  rail  for  ordinary  cranes,  and 
for   special   cranes   requiring  over   an   85-pound   rail,   purchaser 
shall  specify  type  and  size  of  rail. 

(g)  The   standard  tread  diameters  of  trolley  track  wheels 
shall  be  12,  15,  18,  21  and  24  inches. 


8  A.  I.  &•  S.  H.  E.  CRANE  SPECIFICATIONS 

(h)     The  standard  bores  of  these  wheels  shall  be  as  follows: 

12-inch  diameter  3^-inch  bore 

15-inch  diameter  35^-inch  bore 

18-inch  diameter  45^-inch  bore 

21-inch  diameter  5%Hnch  bore 

24-inch  diameter  5^-inch  bore 

(i)  With  maximum  load  on  crane  track  wheel  bearing- 
pressures  must  not  exceed  750  pounds  per  square  inch  projected 
area. 

26.  Bridge  Girders. 

Top  and  bottom  cover  plates  and  angles  of  box  section 
girders  shall  be  in  one  piece  throughout  the  girder  length,  but 
splicing  of  approved  design  will  be  allowed  in  web  plates.  Web 
plates  shall  be  not  less  than  5/16-inch  thick.  The  top  cover 
plate  of  box  girders  carrying  rails,  shall  be  supported  at  frequent 
intervals  by  structural  steel  distance  pieces  which  shall  bear 
against  it  and  be  riveted  to  both  web  plates.  Girders  shall  be 
rigidly  fastened  to  end  trucks  and  shall  be  tied  together  at  top 
and  bottom  by  plates  which  shall  be  as  broad  as  possible  without 
interfering  with  the  trolley  travel.  To  further  assist  in  keeping 
crane  "square"  and  stiff,  a  heavy  angle  shall  be  riveted  across 
top  of  girders  at  extreme  ends,  and  the  entire  end  covered  by  a 
plate  riveted  to  this  angle,  to  angles  on  end  of  all  web  plates, 
and  riveted  or  bolted  to  end  carriages.  Box  girders  shall  be 
drained  to  prevent  accumulation  of  oil  and  water,  holes  to  be 
not  less  than  ^4-inch  diameter. 

27.  Rails  for  Trolley. 

Rails  for  trolley  cross  travel  shall  be  of  only  open  hearth  steel. 
Joints  shall  be  made  by  means  of  standard  splice  bars,  and  pro- 
vision shall  be  made  to  prevent  creeping  of  rails  on  girders.  Rails 
shall  be  fastened  in  place  by  steel  clamps  and  through  bolts  spaced 
not  more  than  36  inches  on  centers,  and  those  on  one  side  shall 
have  a  lead  of  about  three  inches  over  those  on  the  other  side. 

The  standard  trolley  rails  shall  be  60  and  85  pound  sections. 

28.  Bridge  Drive. 

The  line  shaft  pinion  shall  drive  directly  into  the  track  wheel 
gears. 


A.  I.  &  S.  E.  E.  CRANE  SPECIFICATIONS  9 

29.  Operator's  Cab. 

(a)  Cab  shall  be  made  of  structural  steel  and  be  of  fire- 
proof  construction.      It   shall   be   of   weather-proof   construction 
if  crane  is  to  be  operated  on  outdoor  runways.     It  shall  be  made 
substantial  and  rigid  by  proper  gusset  plates  and  bracing,  but 
such  bracing  shall  not  interfere  with  access  to  cab  or  vision  of 
the   operator.      Particular   attention   to   be   given   these    features 
in  case  cab  is  located  at  center  of  bridge. 

(b)  Such  slope  as  the  roof  may  have  shall  be  toward  the 
rear  of  the  cab.     Floor  shall  be  extended  to  form  a  landing  plat- 
form outside  the  door,  which  platform  shall  be  equipped  with 
standard  railing. 

(c)  A  suitable  warning  signal  appliance  shall  be  provided. 

30.  Trolley. 

(a)  Side   frames  of  trolley  shall   be  of   cast  or  structural 
steel.     The  requirements  for  bridge  end  carriages  shall  apply  as 
far  as  possible  to  side  frames.     Frames  shall  be  connected  with 
structural   steel   cross   girts.     Drum   bearings   and   supports    for 
sheaves  shall  be  located  so  as  to  equalize  the  load  on  track  wheels 
as  nearly  as  possible. 

(b)  Wheel  fenders  as  described  in  specifications  for  bridge 
end  carriages  shall  be  attached  to  the  trolley  frame  at  each  end 
of  each  side  frame. 

(c)'  Trolley  to  have  floor  plate  under  motors,  shafts,  drums, 
etc.,  forming  a  working  platform  with  provision  made  for  reach- 
ing footwalk  on  either  side  of  frame. 

31.  Drums. 

(a)  Drums  shall  be  keyed  to  their  shafts  on  driving  gear 
end.     They  shall  have  turned  grooves  of  depth  equal  to  one-half 
the   diameter   of   the    rope,    and   pitch   at   least    l/$    inch   greater 
than  this  diameter.    They  shall  be  designed  so  as  to  leave  not  less 
than  two  complete  wraps  of  the  rope  on  drum  when  hook  is  in 
the  lowest  position.     They  shall  have  flanged  ends  of  depth  and 
thickness  as  required  for  size  of  cable. 

(b)  Pitch  diameter  of  drums  shall  be  not  less  than  30  times 
diameter  of  hoisting  rope. 

(c)  Where  a  drum  for  lifting  magnet  cable  is  specified  it 
must  be  so  located  that  cable  will  not  interfere  with  hoist  ropes- 


10  A.  I.  &  S.  E.  E.  CRANE  SPECIFICATIONS 

Weather  protection  shall  be  provided  for  magnet  cable  drum  on 
cranes  for  outdoor  service. 

(d)  The  crane  builders  shall  use  the  motor  manufacturers 
standard  gear  ratios. 

32.     Brakes. 

(a)  Unless  otherwise  specified,  and  where  direct  current  is 
used,   lowering   shall    be   by    electro-dynamic    control    with    one 
magnetic  brake  on  armature  shaft  of  hoist  motor. 

(b)  Magnetic  brakes  shall  be  capable  of  retarding  the  full 
load  at  double  speed  and  holding  same  when  stopped,  unaided  by 
other  brakes. 

(c)  Brake  wheels  shall  be  accurately  balanced. 

(d)  Brake  coils  shall  be  so  designed  that  the  temperature 
rise  shall  not  exceed  that  of   motor  and  shall  be  protected  by 
metal  casing. 

(e)  Brakes   for  same  size  motor  shall  be  alike  and  inter- 
changeable. 

(f)  Mechanical   retaining   brakes,   if    specified   shall   be   of 
sufficient   capacity   to   absolutely  prevent   load    from   descending 
unless  motor  is  revolved  by  power  in  the  lowering  direction. 

(g)  Foot  brake  shall  be  provided    for    bridge    movement, 
capable  to  stop  crane  under  any  load  condition  with  100  pounds 
pressure  on  foot  lever  in  a  distance  not  exceeding  10  per  cent 
of  the  speed  in  feet  per  minute  at  which  the  crane  is  traveling 
when  the  brake  is  applied. 

(h)  Means  shall  be  provided  to  prevent  any  parts  of  brake 
from  falling  to  the  ground  in  case  they  become  detached  or 
broken. 

33.  Sanders. 

Track  sanders  .operated  from  the  cab  by  the  crane  operator, 
shall  be  provided  for  sanding  the  runway  rails  when  the  rails  are 
too  slippery  at  any  time  for  operating. 

34.  Ropes. 

(a)  Ropes  shall   be   suitable   for  the   service   they  are  cm- 
ployed  for. 

(b)  Where  double  ropes  are  provided    for    safety    or    for 
double  drive,  each  rope  shall  have  the  same  capacity  that  would 
be  required  if  only  one  rope  was  provided. 


A.  I.  &  S.  B.  B.  CRANH  SPECIFICATIONS  11 

35.  Sheaves  and  Blocks. 

(a)  Sheaves   shall   be    bronze   bushed    and    have    finished 
grooves  not  less  than  \V2  times  the  diameter  of  the  rope. 

(b)  Sheaves  shall  have  a  pitch  diameter  not  less  than  30 
times  the  diameter  of  the  rope  and  shall  be  protected  by  guards 
which  fit  close  to  the  flanges  so  as  to  prevent  rope  coming  off. 

(c)  Bottom  block  shall  be  of  structural  steel  and  plates,  and 
hook  shall  swivel  on  ball  bearings  so  constructed  as  to  exclude 
dirt.     All  parts  of  block  shall  be  so  arranged  as  to  be  readily 
lubricated,  grease  cups  being  so  located  as  to  be  protected  from 
injury  as  far  as  practical. 

(d)  All  sheaves  to  have  guards,  to  keep  rope  in  grooves. 

36.  Conductors. 

Conductors  across  the  bridge  shall  be  of  rigid  type. 

37.  Motors  and  Controllers. 

Purchaser  shall  specify  make,  type  and  sizes  of  motors  and 
controllers  to  be  used. 

38.  Wiring. 

(a)  Purchaser   shall   submit  detail   wiring  specifications   or 
install  his  own  wiring. 

(b)  An  enclosed  double  pole  safety  switch  shall  be  mounted 
on  the  foot  walk  adjacent  to  the  cab  and  be  so  connected,  that 
it  will   disconnect  the   main  circuit  between   the   collectors  and 
the  switchboard. 

39.  Switchboard. 

A  protective  switchboard  panel  shall  be 'provided.  Location 
and  type  to  be  specified  by  the  purchaser. 

40.  Limits. 

Overtravel  limits  shall  be  provided.  They  shall  open  main 
motor  circuit  at  any  predetermined  point,  and  where  limited 
space  for  travel  may  require  it,  dynamic  braking  shall  be  applied 
to  prevent  drifting  of  load. 

41.  Painting. 

All  structural  work  and  parts  usually  painted  shall  be  thor- 
ougly  cleaned  and  painted  with  two  coats  of  paint.  Parts  that 


12  A.  I.  &•  S.  E.  E.  CRANE  SPECIFICATIONS 

are  inaccessible  after  they  are  assembled  shall  be  cleaned  and 
painted  before  assembling. 

42.     Safety  Devices. 

In  addition  to  the  safety  appliances  specified  in  these  General 
Specifications  the  builder  shall  supply  and  install  all  appliances 
necessary  for  compliance  with  the  Factory  Laws  of  the  State 
in  which  the  crane  is  to  be  operated. 

APPENDIX  A 

HOT    METAL    CRANES 

1.  For  cranes  handling  hot  metal  the  following  additional  speci- 
fications shall  apply: 

2.  Operator's  Cab. 

(a)  Operators'   Cabs   shall  be  so  constructed   as   to   enable 
the  operator  to  completely  enclose   himself   by   means  of   doors 
and  windows. 

(b)  When  crane  is  handling  molten  metal  and  no  provision 
is  made  for  the  quick  escape  of  operator,  by  runway  or  other 
means,  in  case  molten  metal  gets  spilled,  there  shall  be  provided 
a  compartment  for  operator  to  get  into  that  will  resist  unbear- 
able heat  for  at  least  10  minutes.    The  door  to  such  compartment 
shall  be  at  least  18  inches  wide  and  it  must  be  so  attached  that 
it  can  be  tightly  closed. 

(c)  Cab  that  will  be  subject  to  heat  from  below,  shall  have 
a  shield  plate  not  less  than  3/16  inches  thick,  six  inches  below 
floor  of   cab.      It   shall   be   attached   with   bolts   having   spacing 
sleeves  on  them. 

3.  Trolley. 

On  cranes  for  handling  molten  metal,  where  the  main  hoist 
drums  carrying  two  sets  of  ropes  are  driven  by  two  motors,  each 
through  its  own  train  of  gears,  each  motor  and  set  of  gears 
must  be  capable  of  handling  the  full  load  independently  of  the 
other. 

4.  Brakes. 

(a)  Each  main  hoist  on  a  hot  metal  crane  shall  be  equipped 
with  two  magnetically  operated  brakes,  one  mounted  on  end  of 


A.  I.  &•  S.  H.  H.  CRANE  SPECIFICATIONS  13 

armature  shaft,  the  other  on  intermediate  shaft  as  near  the  drum 
as  is  practicable. 

(b)  Each  brake  shall  be  capable  of  stopping  the  full  load, 
lowered  at  twice  the  hoisting  speed,  and  holding  the  load  when 
stopped  unassisted  by  other  brakes. 

(c)  Each  brake  to  comply  with  paragraph  32  General  Speci- 
fications as  to  construction. 

5.  Ladle  Hooks. 

(a)  Ladle  hooks   for  hot  metal  ladle  shall  be  either  built 
up  of  laminated  plates  or  made  of  heat  treated  forgings. 

(b)  Ladle  hooks  shall  be  provided  with  wearing  slippers  of 
suitable  material  (if  specified). 

(c)  Locks   to   hold   the   ladle   in   vertical   position   shall   be 
attached  to  the  hook  so  that  they  can  be  seen  from  the  operator's 
cab.     Means  shall  be  provided   for  holding  the  lock  out  when 
tipping  the  ladle. 

6.  Separators. 

Separators  for  hot  metal  ladle  hooks  shall  be  of  structural 
steel,  and  shall  be  protected  from  heat  by  plate  guard,  separated 
from  beam  by  spacing  sleeves. 


NOTES 


NOTES 


NOTES 


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